MODIFIED SCREEN PRINTED ELECTRODES FOR GLUTATHIONE DETECTION

摘要

The use of screen printed electrodes (SPE) based on graphite ink modified with Prussian Blue (PB) as probes for thiols detection is reported. The catalytic effect of Prussian Blue towards thiol oxidation has been fully investigated in this study. Evidence of the mediated oxidation of thiols by Prussian Blue at the electrode surface, has been observed in cyclic voltammetry experiments. High amperometric responses were recorded for cysteamine (detection limit=10?6M), at a selected potential of 200mV, where no detectable signal was observed for the oxidised form (i.e. RS-SR) of the thiol cystamine. A disulfide exchange reaction has been used for the amperometric detection of the biologically important thiol glutathione with these sensors.